In the living environment, there exists light with various wavelengths. Such light reportedly affects the human body and mind. For example, in Non-Patent Document 1, it is reported that the internal clock is improved by exposure to sunlight, and the like. Further, in Non-Patent Document 2, it is reported that light emitted from light-emitting diode (LED) lighting, a liquid crystal display that uses an LED for a backlight, and the like, which have existed in the living environment in recent years, significantly affects the body and mind.
There have also been several reports on the effects of light on the eyes. For example, in Non-Patent Documents 3 and 4, the eye reportedly sustains various damage when exposed to ultraviolet light. For that reason, many products, such as eyeglasses and contact lenses, that minimize the transmission of ultraviolet light to the extent possible to prevent eye exposure to ultraviolet light that may cause damage are now commercially available.
Further, in Non-Patent Document 5, outdoor activity in sunlight is described as related to the suppression of myopia. Further, in Patent Document 1 and Non-Patent Document 7, it is proposed that light having a specific wavelength is effective in myopia prevention. With the number of persons with myopia continually on the rise worldwide in recent years, means for preventing the occurrence and means for delaying the progression of such myopia are in high demand.